Over the last few years I’ve been rather impressed by the fearfulness expressed by the dermatologists concerning their chosen nemesis: the sun. It appears that Dr. Richard Weller (I think I have the proper Richard Weller in that link) doesn’t agree with his colleagues, as noted in this opinion piece published in NewScientist (13 June 2015, paywall):
This is, of course, quite correct. A vast body of evidence links sun exposure to skin cancer. What is lacking, however, is any evidence that sunlight is bad for you, if by “bad for you” we mean it shortens life. Ask a dermatologist about the evidence that sunshine raises your risk of dying and there will be an embarrassing silence. After a century of knowing the link between sunshine and skin cancer, this is not good enough. In fact, there is increasing evidence that keeping out of the sun may be killing you – and in more ways than you think.
It helps if the inquirer is a fellow doctor, I suspect.
People with the highest vitamin D levels tend to be healthier. They are less likely to have high blood pressure, diabetes, strokes or heart attacks – in fact, they are less likely to die prematurely of any cause. This raised hopes that a simple vitamin supplement could reduce lots of major causes of death.
Many studies have now tested the effects of vitamin D supplements on health, but the results have been disappointing. …
My group has found another mediator that brings us benefits from sunlight: nitric oxide. Its apparent simplicity belies its importance. Nitric oxide has many roles, but a major one is the Nobel prizewinning discovery that it dilates blood vessels and controls blood pressure. In 1996, we discovered that the skin produces this gas. This is because the skin contains large stores of nitrate, which the ultraviolet (UV) radiation in sunshine converts into nitric oxide. When this gas enters the circulatory system, it lowers blood pressure by a small amount. This can make a big difference. …
Sun-produced nitric oxide may also help explain some blood pressure puzzles – why the average blood pressure of the UK population is lower in summer than winter, for example, and the correlation between latitude and blood pressure, with people living closer to the equator having lower blood pressure than those at higher latitudes.
And, in general?
A survey of 30,000 Swedish women recruited in 1990 and questioned about their sun-seeking behaviour found that the more they had sunbathed, the less likely they were to have died 20 years later. In fact those who did the most sunbathing were half as likely to be dead as those who had avoided the sun entirely. The authors calculate that 3 per cent of deaths in Sweden are due to insufficient sun exposure. Other research backs this up. Another Scandinavian study of 40,000 women found that those who went on the most sunbathing holidays were least likely to have died 15 years later.
And
In fact, a study of the over-40s in Denmark found that those with non-melanoma skin cancer were less likely to die than healthy controls, and much less likely to have a heart attack. So when I diagnose it in my patients, the first thing I do is congratulate them.
A big, juicy article. While keeping in mind that this appears to be cutting edge research, possibly not yet replicated, I do think I’ll be getting a little more sun during the summer.
Still not doing that nude sunbathing in January. Not in Minnesota.
